A barcode includes a combination of white and black bar-shaped portions which represent a binary code. Barcodes are used to input data quickly and they are easy to read for a computer. A barcode may have a form that is automatically read by an optical mark reader connected to a computer and then, is input to the computer and stored or recognized. A barcode indicates a type of product complying with a universal product code (UPC), or is used for a point-of-sales (POS) system of sales information in supermarkets and the like. The price of a product corresponding to a barcode can be displayed separately on a display device. The barcode is encoded according to a standard such as the UPC, and then, is decoded through a reader formed with a barcode scanner and a decoder. If the scanner reads the barcode, the code is transferred to the decoder, and the code is decoded so that the code can be transformed into information that can be understood. Decoding of information in the barcode is performed by the scanner. A black bar that is a black bar portion of the barcode allows a small amount of light to be reflected to the scanner, while white space bars positioned between black bars reflect more light. The difference between amounts of reflected light can be translated into an electrical signal by a photo detector in the scanner, and the signal can be read.
In the reading of a barcode, hand held scanners were used in the past. More recently, laser-type scanners have been mainly used. In the laser type, a barcode is automatically read by moving a product on which the barcode is printed, across a reader such that the work can be made more efficient. In a factory automation field, a barcode is attached to an object to be processed so that it can help with the identifying of various items required for a job by recognizing a lot number and a product number. Also, a barcode can be used for a variety of purposes including sales information in a shop, and management of books, proof of identification and identification of products in a library. A barcode can be printed on a variety of materials in addition to paper, and has an advantage that desired information can be quickly accessed. However, since the capacity of information in the barcode is limited, the barcode has a drawback that not all types of information regarding a product can be fully known from the barcode. In order to compensate for this drawback, a 2-dimensional (2D) barcode, i.e., a matrix code, has been developed recently.
Though the 2D barcode does not have a big difference from the conventional barcodes, it can include more information because about 4,000 characters can be coded in a mosaic-type arrangement of black and white rectangles instead of the linear arrangement used in the conventional linear barcodes. However, these 2D barcodes have the following two problems. Firstly, the barcode can be copied such that reliability and accuracy of information obtained from the barcode is lowered. Secondly, the amount of information of all conventional barcodes, including the 2D barcodes, is limited because information is expressed in a binary code by white and block. Accordingly, in order to overcome these problems, an embodiment of the inventive concept provides a liquid barcode in which a series of a plurality of chambers are formed as bar-shaped liquid bars and arranged in parallel.
The conventional credit card adopts a magnetic recognition method. If a magnetic card such as a credit card is passed through an automatic teller machine (ATM) or a card reader by a user, magnetic information recorded in the card is transformed into an electrical signal. The signal is transferred into the inside of the reader, and is transformed into a predetermined binary code, thereby inputting information included in the card. For a magnetic card, a magnetic tape is attached to a PVC card such as an ordinary credit card, and then used. The magnetic recognition method is widely used because it allows recording of basic information and easy recording and deleting of additional information. However, the method has a problem that copying is possible.